
12/03/2025
Respiratory syncytial virus (RSV) is a common, highly contagious virus that spreads between people when small water droplets produced by an infected person when they are speaking, coughing or sneezing is inhaled by others or land on a surface.
In adults and older, healthy children, RSV typically causes mild symptoms that mimic common cold. However, it can cause severe infection in some people, including but not limited to babies aged 12 months and younger, especially premature infants or anyone with a weak immune system.
Within the first few weeks of receiving the RSV vaccine, a pregnant woman's immune system produces antibodies against the virus. These antibodies then travel across the placenta into the baby's bloodstream to protect them against RSV up to six months from birth.